Police video released Tuesday shows a man brazenly swipe an 86-pound bucket of gold worth $1.6 million from the back of an unattended armored truck in Midtown before scampering away, NYPD officials said. The suspect first cased the open Loomis International truck as it parked outside 48 W. 48th St., near Sixth Avenue, while two guards went into a nearby building for another pickup about 4:30 p.m. Sept. 29, police said. Realizing no one was looking, he then grabbed a black 5-gallon bucket carrying 86 pounds of gold flakes bound for Ontario and ran away with it in his arms, police said.